The present invention relates to surgical needles and, more particularly, to specifically curved surgical needles for use in ophthalmic surgery, microsurgery and similar surgical procedures.
Surgical needles are generally either straight, ski-shaped, or uniformly curved. For many surgical procedures including eye operations and microsurgery, the curved needles have gained wide acceptance. These needles have a uniform radius and the length of the needle may be from about a quarter of a circle to 2/3rds of a circle; that is, from about 90.degree. to about 240.degree.. The curve in the needle is helpful to the surgeon in placing the suture in that the surgeon usually grasps the body of the needle near its center and inserts the pointed end into the edge of the tissue to be closed. Provided the surgeon keeps a general forward motion along the direction of the shape of the curve of the needle, the needle will tend to place the suture at the desired depth and take the desired "bite" by a controlled emergence of the needle from the tissue. The smaller and more fragile the material being sutured the more difficult it is to suture. Also, the tighter the area in which the surgeon is working, the more difficult it is to suture. These problems are very prevalent in eye surgery. The placing of the suture is critical to success in many eye operations. For example, in a corneal transplant operation, the sutures must be uniformly placed as to depth and length of bite so that the suture loops attain substantially equal tension around the entire transplant circumference. If some sutures have more or less tension than other sutures, or some sutures have been placed at different depths or lengths of bite than others, the results of the operation may not be as successful. Also, the standard curved needle when gripped in the center portion by the needle holder, if gripped too tightly, the area gripped will tend to be straightened. This slight straightening of the center portion increases the difficulty the surgeon has in placing uniform suture loops.
The prior art shows various surgical needle configurations to improve specific suturing techniques. In U.S. Pat. No. 3,556,953 there is disclosed a microminiature suture needle which may be either straight, ski-shaped or curved. In U.S. Pat. No. 3,877,570 there is disclosed a specifically curved needle specifically designed for attaching hair pieces to the human scalp.
Other various shaped surgical needles for improved suturing are described in U.S. Pat. Nos. 3,918,455, 4,128,351, and 4,237,892.
It is also known that a specifically curved needle for opthalmic surgery is being sold for corneal scleral closures by the Alcon Company. This needle is more fully disclosed in an article which appeared in the Am. Intra-Occular Implant Soc. J. 6, 282-284 (1980). Though many of these prior art surgical needles solve some of the problems with regard to the specific procedure for which they were designed, none of them solve all of the problems involved in the suturing techniques required in ophthalmic surgery or in microsurgery or other similar surgical procedures. In ophthalmic surgery, as well as in other surgery, it is important the needle be as sharp as possible. The sharper the needle the less the damage or trauma the needle causes to the tissue being sutured. However, the sharper the needle the less the "feedback" or response the surgeon feels when using the needle and the more difficult for the surgeon to know exactly where the suture is being placed and the depth to which the suture is placed. Also, when the needle is extremely sharp and there is little "feed-back", it is difficult for the surgeon to be certain that each placement of the suture is the same as the previous placement. When using a standard smoothly curved needle in ophthalmic surgery, the surgeon places some torque on the needle to bring the needle appropriately through the tissue. With the desired very sharp needle and, hence, little "feedback", it is very difficult for the surgeon to place the same amount of torque on each placement of the needle and, hence, it is extremely difficult to produce the uniformly tensioned suturing desired in ophthalmic surgery.
What we have discovered is a new and improved surgical needle which reduces the trauma to the patient and provides the needle be placed to the right depth in the tissue and grabs or sutures the right amount of tissue as the suture is being placed. Also, our newly configured needle requires minimal manipulation in placing the suture through the tissue. Furthermore, our newly configured needle allows for improved suturing of fine fragile tissue and allows such suturing to be conducted in very tight and confined places while reducing the possibility of injury to adjacent tissue.
Our new needle may be made as sharp as possible because "feedback" is surprisingly no longer required with our new needle. The specific geometry of our new needle eliminates the requirement of "feedback" because it unexpectedly automatically controls the placement of the suture and surprisingly places each suture in an identical manner. Our new needle has less tendency to be straightened by the needle holder. Our new needle allows for the suturing of delicate corneal tissue accurately and consecutively in a very uniform manner with the desired bite and grasp of the tissue being sutured.